Lee San, vice president of the conglomerate group Lee San. He was adopted by Chairman Lee, but unlike the chairman's real son Lee Tae-gon, he has won the trust of the chairman with his seriousness and sincerity. One day, Tae-gon, who was a haphazard and reckless man, suddenly says, "I want to learn how the company works," and begins to achieve unexpected results. Then, faced with the threat of losing everything he has built up, San finally makes up his mind. "I will tame this self-centered young master myself."